Problem: Khan.scratchpad.disable(); For every level Tiffany completes in her favorite game, she earns $450$ points. Tiffany already has $310$ points in the game and wants to end up with at least $3600$ points before she goes to bed. What is the minimum number of complete levels that Tiffany needs to complete to reach her goal?
Answer: To solve this, let's set up an expression to show how many points Tiffany will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Tiffany wants to have at least $3600$ points before going to bed, we can set up an inequality. Number of points $\geq 3600$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3600$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 450 + 310 \geq 3600$ $ x \cdot 450 \geq 3600 - 310 $ $ x \cdot 450 \geq 3290 $ $x \geq \dfrac{3290}{450} \approx 7.31$ Since Tiffany won't get points unless she completes the entire level, we round $7.31$ up to $8$ Tiffany must complete at least 8 levels.